Showing papers in "Journal of Assisted Reproduction and Genetics in 1986"
TL;DR: EQ and EDR were significantly associated with each other and together provide a valuable guide in predicting pregnancy, in selecting embryos for freezing, and in monitoring day-to-day performance in the in vitro fertilization (IVF) program.
Abstract: Two systems for measuring embryo development in vitro were evaluated. One was a 1-4 scale based on a subjective evaluation of embryo quality (EQ) from microscopic appearance. In addition, a formula for scoring embryo growth rate in vitro was developed. The embryo development rating (EDR) was based on the ratio between the time at which embryos were observed at a particular stage after insemination and the time at which they would be expected to reach that stage in a hypothetical "ideal" growth rate with a cell cycle length of 11.9 hr. Using this scoring system, "normally" growing embryos scored 100. This approach was aimed at partially normalizing the data and allowed all embryos to be analyzed similarly regardless of the time of observation. Analysis of 1539 embryo replacements resulting in 232 clinical pregnancies showed that both EDR and embryo-quality scores were of value in predicting success, with clinical pregnancy most likely to eventuate from a combination of moderate to good EQ scores (2-4) coupled with average or above-average growth rates (EDR scores from 90 to 129). Poor-quality and very slowly or very rapidly growing embryos were underrepresented in cycles that proceeded to pregnancy. These inferences were based on all embryos transferred (mean, 2.73 per transfer cycle), and they were substantiated by an analysis of 33 pregnancies resulting from replacement of a single embryo and from 18 pregnancies in which all embryos scored the same with both systems. EQ and EDR were significantly associated with each other and together provide a valuable guide in predicting pregnancy, in selecting embryos for freezing, and in monitoring day-to-day performance in the in vitro fertilization (IVF) program.
494 citations
147 citations
TL;DR: The possibility that differences in U values between groups are due to different ovarian stimulation protocols is discussed, as is the values of the UE model in highlighting differences between IVF groups and its importance in predicting multiple pregnancy rates.
Abstract: A comparison of the implantation rates following in vitro fertilization (IVF) and embryo transfer (ET) for four major groups indicates differences in the implantation rates as well as in the incidence of multiple implantation. By assuming that the probability of implantation is the product of two variables, uterine receptivity (U) and embryo viability (E), estimates for U and E are derived for each of the four IVF groups using maximum likelihood methods. The UE model is tested using chi-squared goodness-of-fit methods for predicted implantation rates versus observed. The possibility that differences in U values between groups are due to different ovarian stimulation protocols is discussed, as is the value of the UE model in highlighting differences between IVF groups and its importance in predicting multiple pregnancy rates.
106 citations
TL;DR: It is demonstrated that significantly more expanded blastocysts survive cryopreservation than cleaving embryos, and faster-growing embryos did not survive better than slowly growing embryos, but the incidence of implantation was higher with faster-developing embryos.
Abstract: Five- to ten-cell embryos and expanded blastocysts from 68 patients were thawed in an attempt to establish pregnancy. Three fresh embryos had been replaced unsuccessfully in these patients. Forty-five patients had intact freeze-thawed embryos replaced and 12 became clinically pregnant. Ten of these pregnancies have now advanced beyond week 24. The preliminary results presented here demonstrate that significantly more expanded blastocysts survive cryopreservation than cleaving embryos. Faster-growing embryos did not survive better than slowly growing embryos, but the incidence of implantation was higher with faster-developing embryos. Significantly more blastocysts with a “normal” morphology survived cryostorage than those scored as “irregular” (77 versus 7%). A similar trend was observed when normal and irregular cleaving embryos were frozen, but the difference was not significant. The severity of contraction of blastocysts upon the addition of cryoprotectant increased the incidence of survival. The proportion of patients whose embryos had holes in the zona pellucida following cryopreservation was significantly higher when embryos were frozen at the cleaving stage (39%) rather than the expanded blastocyst stage (16%). Almost all embryos with damaged zonae degenerated. The proportion of cleaving embryos that survived cryostorage was inversely correlated with the number of follicles aspirated.
69 citations
TL;DR: A randomized control trial involving the fertilization and culture of human embryos in culture medium conraining either 10% maternal serum or no protein or amino acid supplement found no difference in fertilization rates, development of apparently normal embryos, pregnancy rate, or birth rate between protein-containing and protein-free media.
Abstract: A randomized control trial involving the fertilization and culture of human embryos in culture medium (T6) conraining either 10% maternal serum or no protein or amino acid supplement was carried out to assess the effect of deletion from culture of all fixed nitrogen on fertilization, embryo development, and embryo viability. There was no difference in fertilization rates (68 vs 69%), development of apparently normal embryos (96 vs 97%), pregnancy rate (18 vs 14%), or birth rate (13 vs 11%) between protein-containing and protein-free media. Deletion of protein from the culture medium may enable the constitution of more appropriate and defined culture media for human in vitro fertilization (IVF).
67 citations
TL;DR: A prospeative randomized study of 100 replacements showed that no better pregnancy rate was obtained by placing patients in the knee-to-chest rather than the dorsal position and the addition of a rigid external sleeve to the catheter did not provide any advantage.
Abstract: One hundred forty-six embryo transfers were carried out in the In Vitro Fertilization (IVF) Clinic at St. Pierre Hospital, Brussels, between November 1983 and February 1985. In each of these cases a series of characteristics of the replacement procedure was systematically recorded. Analysis of these data in relation to pregnancy rates indicated that no significant differences appeared among three different operators, the absence or occurrence of cervical bleeding and subjective evaluation of the procedure were related to the chances of establishing a pregnancy, and the duration of replacement had no influence on the outcome of trials. A prospective randomized study of 100 replacements showed that no better pregnancy rate was obtained by placing patients in the knee-to-chest rather than the dorsal position and the addition of a rigid external sleeve to the catheter did not provide any advantage. A simplified method of replacement is thus advocated.
66 citations
TL;DR: The study reveals that fertilization is significantly reduced (P<0.001) only if both IgA and IgG antibodies are present in semen but there is no reduction if either class is present alone.
Abstract: Seventy-two couples, including 15 with antispermatozoal antibodies in the male partner's semen, were studied in a program of in vitro fertilization and embryo transfer. Cases were further subclassified as normospermic or oligospermic and antispermatozoal antibodies were assessed with categorization into the respective human immunoglobulin classes as determined using the indirect immunobead test. The study reveals that fertilization is significantly reduced (P less than 0.001) only if both IgA and IgG antibodies are present in semen but there is no reduction if either class is present alone. The fertilization rate of oocytes is significantly reduced (P less than 0.001) by sperm from oligospermic samples, and there is a further reduction in those cases with combined IgA/IgG antispermatozoal antibodies.
63 citations
TL;DR: Overall Bayley Scale scores were within the normal range and parents as a group were seen to function well and problems presented were in accordance with those expected in a population of this age range, particularly considering the high incidence of prematurity.
Abstract: Following community concerns regarding the status of children conceived by in vitro fertilization (IVF), 33 children who had received pediatric follow-up were seen for a psychosocial evaluation Parents were interviewed in a semistructured format by a child psychiatrist regarding their child's development, child-centered problems, parental problems, marital issues, parenting experience, and experience of the IVF program The Bayley Scales of Infant Development were administered to the children by a clinical psychologist Children's ages ranged from 12 to 37 months (the majority between 12 and 20 months) There was a high incidence of prematurity and twins in the population seen Twenty-two children had no current problems and seven presented minor problems Of the four with significant developmental problems, two had been very low-birth weight infants with significant neurological problems and one had severe congenital heart disease Overall Bayley Scale scores were within the normal range and parents as a group were seen to function well Problems presented were in accordance with those expected in a population of this age range, particularly considering the high incidence of prematurity
62 citations
TL;DR: One significant and two minor abnormalities were detected and only one infant was slightly under the expected developmental assessment at 1 year on the corrected general quotient of the Griffiths Developmental Scales for children.
Abstract: The pregnancy details, delivery outcome, and developmental status as measured on the Griffiths Developmental Scales are provided on the first 20 infants reaching their first birthday following in vitro fertilization-embryo transfer (IVF-ET) within the PIVET Programme An increased rate of preterm delivery, intrauterine growth retardation, and cesarean sections was noted One significant and two minor abnormalities were detected and only one infant was slightly under the expected developmental assessment at 1 year on the corrected general quotient of the Griffiths Developmental Scales for children
61 citations
TL;DR: Analysis of the data collected to date shows that patients with three or more embryos frozen have a significantly higher pregnancy rate than patients with one or two embryos frozen, and that patients who were pregnant following the initial embryo replacement on the cycle of IVF treatment are more likely to conceive following replacement of their frozen-thawed embryos.
Abstract: Embryo cryopreservation has been studied at Monash University since 1981 and has been available to patients since mid-1983. Of approximately 1200 patients' cycles of in vitro fertilization (IVF), 445 have had excess embryos which they requested to be frozen. To date 205 patients have requested thawing of their embryos and 144 have had frozen-thawed embryos replaced in utero, resulting in 16 pregnancies. Four of these pregnancies aborted, four are ongoing, and eight deliveries have resulted, including one stillbirth at 26 weeks and one set of twins. Analysis of the data collected to date shows that patients with three or more embryos frozen have a significantly higher pregnancy rate than patients with one or two embryos frozen (23 versus 4%, respectively). Embryo viability, but not embryo survival, following freezethawing is related to the degree of embryonic fragmentation and the cell stage at freezing. Eight-cell embryos had a significantly higher viability than other cleavage stages. Those resulting in pregnancy tended to be the faster-dividing eight-cell embryos and were undamaged after freezing and thawing. However, when considering all cleavage stages, there was little effect of freezing damage on embryo viability, providing that at least 50% of the cell complement of embryos were intact and the zona pellucida was undamaged. Nor was there any marked effect of the age of embryos postinsemination. It is also possible that patients who were pregnant following the initial embryo replacement on the cycle of IVF treatment are more likely to conceive following replacement of their frozen-thawed embryos.
51 citations
TL;DR: Mouse embryos at the one, two, and eight-cell stages have been used to optimize the conditions for cryopreservation of human oocytes and embryos, and three pregnancies were established upon the transfer of 11 frozenthawed embryos to seven patients.
Abstract: Mouse embryos at the one-, two-, and eight-cell stages have been used to optimize the conditions for cryopreservation of human oocytes and embryos. For storage in glass vials using 1.5 M dimethyl sulfoxide (DMSO) as a cryoprotectant and slow cooling (≈0.3°C/min), phosphate-buffered medium was superior to Hepes-buffered medium. Termination of slow cooling at −80°C before transfer to liquid nitrogen with subsequent slow thawing (−8°C/min) resulted in more embryos surviving than when cooling terminated at −40°C and rapid thawing (−500°C/min) was employed. Dilution of DMSO upon thawing with medium containing 0.5M sucrose gave higher embryo survival rates than a stepwise (0.25 M decrements) dilution. Using these techniques, three pregnancies were established upon the transfer of 11 frozenthawed embryos to seven patients. Rates of embryo survival using the simpler cryopreservation technique of ice-free vitrification in 0.25-ml straws have been disappointing.
TL;DR: It is shown that the sex ratio and the incidence of aneuploidy are similar, irrespective of the fertilization system used, and male and female gametes have the same levels ofAneuploids.
Abstract: A comparison of the first cleavage-stage chromosome complements of 1022 in vivo fertilized mouse embryos and 1033 in vitro fertilized mouse embryos is reported. The chromosome analysis of first-cleavage embryos allows us to study directly the chromosome complement of the sperm and oocyte that contribute to the embryo, since both chromosome clusters remain separate when an antimitotic agent is used to prevent syngamy. In this paper we show that the sex ratio and the incidence of aneuploidy are similar, irrespective of the fertilization system used. Male and female gametes have the same levels of aneuploidy. Triploidy is more frequent in the in vitro fertilized embryos and the difference can be ascribed to a higher incidence of polyspermy and diploid spermatozoa.
TL;DR: The ultrastructure of preovulatory human oocyte—cumulus complexes was described after inducing maturation by clomiphene, human menopousal gonadotropin (hMG), human chorionic gonad stimulant (hCG) treatment.
Abstract: The ultrastructure of preovulatory human oocyte—cumulus complexes was described after inducing maturation by clomiphene, human menopousal gonadotropin (hMG), human chorionic gonadotropin (hCG) treatment. The majority of the oocytes was at metaphase, II of meiosis, with a radially orientated spindle. The oocyte surface was covered by a multitude of microvilli. Cortical granules were nonuniformly distributed along the cortex. A cytoplasmic polarization was observed. The cytoplasmic organelles were in general uniformly dispersed, with the exception of a narrow segment within which cytoplasmic membranes and mitochondria formed clusters. The spirndle was usually found at the borderline between the two regions of the cytoplasm. The functional significance of this polarization is not yet known.
TL;DR: The frozen storage of mouse embryos is a practical means of assuring the preservation of scientifically valuable strains of mice for research.
Abstract: The frozen storage of mouse embryos is a practical means of assuring the preservation of scientifically valuable strains of mice for research. Banks are maintained at over 15 institutions throughout the world. At the Jackson Laboratory eight-cell embryos from approximately 500 strains are preserved in liquid nitrogen storage.
TL;DR: An approach to predict the volume response of an embryo during cryopreservation using parameters such as cryoprotectant and water permeability coefficients and their temperature coefficients will allow the development or madification of cryop Reservation procedures using relatively few embryos.
Abstract: During a cryopreservation process a preimplantation embryn has to undergo multiple changes in volume caused by osmotic forces. When parameters such as cryoprotectant and water permeability coefficients and their temperature coefficients are known, equations can be solved to predict the volume response of an embryo during cryopreservation. This approach will allow the development or madification of cryopreservation procedures using relatively few embryos.
TL;DR: Stocks of mutant mice have been reestablished from eight-cell embryos stored in liquid nitrogen for varying periods up to 11 years, and no evidence has been found of deterioration of survival with time of storage.
Abstract: Stocks of mutant mice have been reestablished from eight-cell embryos stored in liquid nitrogen for varying periods up to 11 years, and no evidence has been found of deterioration of survival with time of storage. Also, studies on the simulated cumulative effect of background radiation during storage failed to find any detrimental effect when embryos were exposed to the equivalent of about 2000 years of background radiation. However, in some cases embryos that carry mutant genes or chromosome anomalies tend to survive the freezing and thawing procedure less well than F1 hybrid embryos. Although this effect is probably independent of storage time, recent improvements in technique upon embryonic survival are to be welcomed.
TL;DR: This technique offers several crucial advantages: it reduces surgical risk, reduces the length of the patient's stay in hospital as well as the overall cost of the procedure, and it also makes possible puncture in some cases hitherto regarded as excluded.
Abstract: Two hundred twenty-two patients took part in a trial of follicle puncture via the transvaginal route under sonographic control for the purpose of in vitro fertilization (IVF). Induction protocols were mainly human menopausal gonadotropin (hMG)+human chorionic gonadotropin (hCG) and clomiphene + hMC + hCG. In 79.7% oocyte aspiration could be achieved without difficulty via the transvaginal route. An average number of 4.7 oocytes per attempt was obtained: 10.7% evolutive pregnancies were obtained. No major incident was noted. This technique offers several crucial advantages: it reduces surgical risk, reduces the length of the patient's stay in hospital as well as the overall cost of the procedure, and it also makes possible puncture in some cases hitherto regarded as excluded.
TL;DR: It appears, therefore, that oocyte and/or embryo quality may be affected by increased amounts of exogeneous gonadotropin stimulation.
Abstract: The effect of increasing doses of exogenous gonadotropin stimulation for ovarian hyperstimulation was studied utilizing mouse embryos fertilized in vivo or in vitro. Increased rates of embryo degeneration, fragmentation, and triploidy, increased sister-chomatid exchange, and decreased fertilization rates were observed in high-dose stimulation groups. It appears, therefore, that oocyte and/or embryo quality may be affected by increased amounts of exogeneous gonadotropin stimulation.
TL;DR: The data suggest that high P levels and a low E2/P ratio in the early luteal phase might have a favorable influence on the implantation process in human IVF.
Abstract: Luteal phases after in vitro fertilization (IVF) and embryo replacement have been studied in 241 cycles. A positive correlation was observed between the follicular estradiol (E2) peak and the progesterone (P) level on day 3 of the luteal phase, but not correlation was found between the E2-peak value and the luteal-phase duration or midluteal P concentration. When the trials were classified in relation to their outcome (i.e., clinical pregnancies, chemical pregnancies, or failures), the mean P level on day 3 of the luteal phase was significantly higher in clinical pregnancies than in chemical pregnancies and in failures. Mean E2 levels on day 3 were not significantly different among the three groups. Values of the E2/P ratio were significantly higher in chemical pregnancies than in the other groups. No significant differences were observed among the three groups on day 8. When comparing trials ending in failure to those leading to clinical pregnancy for the same patients, pregnancies were obtained in cycles in which early luteal P was higher and the early luteal E2/P ratio was lower than in failures cycles. These data suggest that high P levels and a low E2/P ratio in the early luteal phase might have a favorable influence on the implantation process in human IVF.
TL;DR: It appears that a Hepes medium containing HCO3− is as effective as T6 medium, which uses a gas phase, in supporting in vitro mouse embryonic growth.
Abstract: The purpose of this study was to determine if mouse embryos could be grown successfully in a culture medium devoid of the carbon dioxide phase (CO2). Mouse embryos fertilized in vivo were collected and cultured in Hepes medium with and without bicarbonate (HCO3−) and a phosphate medium with and without HCO3−. In these experiments no CO2 gas phase was used. Further embryos were cultured in Whittingham's modified Tyrode's (T6) medium with a CO2 gas phase and served as controls. The degree of embryonic development was noted. Surviving blastocysts were transferred to the uteri of pseudopregnant mice and delivery at term was allowed to occur. There was no significant difference in the degree of embryonic development in those embryos cultured in T6 or Hepes medium (+HCO3−) or in the number of live offspring obtained when these blastocysts were placed within the mouse uterus. Although embryonic development apparently proceeded successfully in the phosphate (+HCO3−) medium, none of these blastocysts survived when transferred to mouse uteri. No embryonic growth occurred in either the Hepes or phosphate media which were devoid of HCO3−. It appears that a Hepes medium containing HCO3−, which uses no CO2 gas phase, is as effective as T6 medium, which uses a gas phase, in supporting in vitro mouse embryonic growth.
TL;DR: A direct comparison of the penetration of hamster eggs with that of human eggs is the evidence which can validate the usefulness of the sperm penetration assay (SPA).
Abstract: As I stepped down from the podium following my spring 79 presentation (1) concerning the use of the hamster test for differentiating fertile and infertile males, someone said to me, \"'The test won't prove anything until you actually compare the penetration of hamster eggs with that of human eggs.\" Such a direct comparison is the evidence which in fact can validate the usefulness of the sperm penetration assay (SPA). Ubiquitous controversy surrounding the value of the SPA has persisted for the last 7 years. During that time several investigators have attempted to do the necessary comparisons to evaluate the usefulness of the test (Table 1). The pur-
TL;DR: The incidence of the formation of cracks in the zona pellucida during aspiration was assessed by comparing two methods of aspirating follicular contents by suction: (a) mamuat aspiration by syringe and mechanical aspiration by pump.
Abstract: The incidence of the formation of cracks in the zona pellucida during aspiration was assessed by comparing two methods of aspirating follicular contents by suction: (a) mamuat aspiration by syringe and (b) mechanical aspiration by pump. Of 36 patients whose follicles were evcuated manually using syringes, 18 had at least one damaged cocyte. Of 38 other patients whose follicles were aspirated by pump, only one had an oocyte with a cracked zona pelluciada. Four patients had their oocytes aspirated by both syringe and pump. In all four the oocytes were intact when aspirated by the pump, but one oocyte was damaged in three of four cases when the follicles were aspirated using syringes.
TL;DR: The attitudes of anonymous infertile egg donors treated on an in vitro fertilization program toward the donation, the recipient, the potential children conceived, and the recording of information were explored by posted questionnaire.
Abstract: The attitudes of anonymous infertile egg donors treated on an in vitro fertilization program toward the donation, the recipient, the potential children conceived, and the recording of information were explored by posted questionnaire. All donations were made for altruistic reasons and payment of eggs was not expected or given. The majority of donors (91%) wished to withhold their names from the recipient, but half of the donors would not mind if the child contacted them later. Most donors (94%) had told others of their donation and the keeping of records would appear essential for future possible identification. Some possible differences in attitudes between egg and sperm donors were noted but comparisons are difficult due to basic differences in fertility status and ease of gamete collection. The attitudes and characteristics of a control group of infertile women, who were in a position to donate excess eggs but declined, showed no significant differences from those of the donor group, except that they had a significantly greater number who already had one or more children and were less likely to discuss their possible donation with others.
TL;DR: Pregnancy diagnosis was based on the absence of a menstrual period by 20 days after oocyte aspiration coupled with a positive beta-hCG assay at that time and subsequent ultrasonic diagnosis of a growing embryonic sac or sacs.
Abstract: Two liter batches of media were made up using water from a Barnstead Nanopure II system (final resistivity, 18.2 M~t/cm). The batches of media alternated between T6, a modified Tyrode's medium (5), and HTE For gamete and embryo culture the medium was supplemented with 10% (v/v) heat-inactivated pooled patients' serum, while for oocyte aspiration it was supplemented with 20 mM Hepes buffer and 40 IU/ml Na heparin (Flow Laboratories). Final media formulations are given in Table I and are identical to those published by Quinn et at. (2). Each ba tch of medium was made up on a Wednesday and stored in 200-ml Falcon tissue culture flasks at 4~ until the following Saturday, when it was introduced into the system and the previous batch was discontinued. It was not used immediately, as in our hands fresh medium appears to give poor fertilization rates (6) and also so that we could test the medium in growing mouse embryos (7). Batches of medium were alternated on a week-byweek basis. The only exceptions to this general regime were on two occasions when problems with the water system caused us to prolong the use of a batch of medium for 2 weeks (batch 27, T6; and batch 49, HTF) and on one occasion when two batches of HTF were inadvertently prepared back to back (batches 30 and 31). Ovarian stimulation regimes, oocyte recovery techniques, and culture conditions were similar to those reported elsewhere (7-I1). Oocytes were preincubated for 2-16 hr (mean, 7.95 _+ 3.58 hr) before being inseminated with twice-washed spermatozoa (about 50,000/ml). They were checked for signs of fertilization 14-24 hr after insemination, when they were transferred to fresh, preequilibrated medium. Embryos were assessed for microscopic appearance and growth rate at the time of transfer (7). Embryo replacement was 20.5 to 54 hr (mean, 38.6 + 5.64 hr) after insemination. Luteal supplementation was given immediately [4000 IU human chorionic gonadotropin (hCG)] after oocyte aspiration and 5 days (2000 IU hCG) after embryo replacement. Pregnancy diagnosis was based on the absence of a menstrual period by 20 days after oocyte aspiration coupled with a positive beta-hCG assay at that time and subsequent ultrasonic diagnosis of a growing embryonic sac or sacs. ~'Biochemical\" pregnancies based solely on elevated hCG levels were not counted. Patients were assigned to the IVF program from a waiting list of nearly 2000 couples, managed by one of the authors (S.M.E), who in turn had no
TL;DR: A successful pregnancy in a patient suffering from infertility due to severe tubal disease has been achieved following the donation of oocytes by the sister of the recipient following synchronization of ovulation.
Abstract: A successful pregnancy in a patient suffering from infertility due to severe tubal disease has been achieved following the donation of oocytes by the sister of the recipient Both sisters ovulated irregularly and asynchronously The donor's menstrual cycle varied from 24 to 30 days and the recipient's cycle varied from 23 to 26 days Synchronization of ovulation was achieved by matching the onset of their menstrual cycles prior to treatment by in vitro fertilization and by manipulating the follicular phase of both the donor and the recipient during the cycle of treatment Ten oocytes were collected from the donor and all were inseminated with spermatozoa from the recipient's husband Nine normal embryos developed and three were transferred to the uterus of the recipient sister, 55 hr after laparoscopic egg collection A normal singleton pregnancy resulted
TL;DR: Mouse morulae were stored at 0°C in the medium containing various sugars, and their effect on the embryonic viability was examined, and the beneficial effect of sugars seemed to be from proper dehydration of the cells caused by osmotic pressure afforded by a non-toxic and non-permeable non-electrolite.
Abstract: Mouse morulae were stored at 0°C in the medium containing various sugars, and their effect on the embryonic viability was examined. The longevity of the embryos was considerably extended, if a hexose or a disaccharide was supplemented in the medium. The most effective concentration appeared to be 0.5–0.75M, irrespective of the molecular weight. Glucose, galactose, fructose, sucrose and lactose were more effective than mannose and maltose. Considering that the embryos stored with sugars were recovered shrunken, the beneficial effect of sugars seemed to be from proper dehydration of the cells caused by osmotic pressure afforded by a non-toxic and non-permeable non-electrolite. The non-freezing technique using a sugar could also be used combined with a freezing technique, if 1–6 h of incubation is incorporated between the two treatments. If the non-freezing technique prove to be available to the embryos of domestic animals, it will practically be more useful.
TL;DR: Survival of embryos frozen by the present two-step method was high on rapid thawing but poor on slow thaweding, suggesting that the method of rapid freezing permits the formation of some intracellular ice.
Abstract: This paper reports the survival of mouse embryos after freezing when glycol derivatives or erythritol is used as the cryoprotectant and also describes the two-step preservation of mouse embryos (rapid cooling to solid CO2 or liquid nitrogen vapor before transfer to liquid nitrogen). Ethylene glycol was the most effective cryoprotectant of glycols tested and considerable protection against freezing injury was also afforded by propylene glycol. When embryos were frozen in glycerol by a solid CO2 procedure or liquid nitrogen vapor, a relatively high survival was obtained but the survival was lower than that of embryos frozen slowly. Sucrose dilution of glycerol from the embryos frozen-thawed rapidly improved the survival rates. Survival of embryos frozen by the present two-step method was high on rapid thawing but poor on slow thawing, suggesting that the method of rapid freezing permits the formation of some intracellular ice.
TL;DR: It is concluded that there should be no need for any kind of serum addition to fertilization media and the previous observation that the use of serum seems to be beneficial as embryo replacement medium is proved.
Abstract: The use of heat-inactivated patient serum as both fertilization and embryo replacement medium was compared in a prospective randomized study with a fully synthetic culture medium containing human serum albumin without serum addition (B3 INRA Menezo). Another series of the author's IVF program was analyzed retrospectively when a commercially available synthetic medium with bovine serum albumin (B2 INRA Menezo) or B3, as mentioned above, was used without serum addition for fertilization but with 50-100% patient serum as embryo replacement medium. Fertilization rates were significantly higher in the synthetic culture media (70%) than in serum (57%). The rate of polyploid fertilization was significantly lowest in B3 medium. There was a clear trend toward better pregnancy rates when high-percentage or 100% patient serum was used for embryo replacement, no matter if one, two, three, four or more embryos were replaced. We conclude that there should be no need for any kind of serum addition to fertilization media. The present study proves our previous observation that the use of serum seems to be beneficial as embryo replacement medium. This might well be explained by a "protein stick effect" due to the high macromolecular contents of serum rather than by viscosity measurements, since no significant increase in viscosity was observed when a high percentage of serum was added to culture media.
TL;DR: This paper details the first reported case of a triplet pregnancy comprising a unilateral twin tubal gestation in association with an intrauterine pregnancy ending in the live birth of a full-term infant.
Abstract: Two recently published reports of triplet pregnancies following in vitro fertilization and embryo transfer (IVF-ET) have described single tubal gestations in combination with twin intrauterine pregnancies (1,2). This paper details the first reported case of a triplet pregnancy comprising a unilateral twin tubal gestation in association with an intrauterine pregnancy ending in the live birth of a full-term infant.